设计大功率激光器光腔的一些基本原则

由于“对流的”散热效率远大于“扩散的”散热效率,为避免因基态温升过高而使激光下能态输空受对阻塞的“瓶颈效应”,现有重要的大功率激光器,如气动激光器、横流放电CO_2激光器、化学激光器、氧碘激光器等,都采用流动的气体激活介质,这些器件还都在介质组分上采用由储能介质的激发态向激光介质的上能态转移能量的方式提高器件的激光能量转换效率

In-situ SERS of formic acid electro-catalytic oxidation on Au-core@Pt-shell/Pt electrode

Au-core@Pt-shell nanoparticles were synthesized by chemical reduction method. The samples were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). In-situ surfac-enhanced Raman scattering (in-situ SERS) spectroscopy combined with cyclic voltammetry was utilized to investigate the electro-oxidation behavior of formic acid adsorbed on Au-core@Pt-shell nanoparticles coated on platinum electrode, and SERS spectra with high quality were acquired. Results showed that the intermediates COad and HCOOad, the dissociated products of HCOOH, were produced at open circuit potential. As the potential moved to positive, the first oxidation wave for CO, was observed at +0.10 V. The study demonstrated that the electrode prepared by Au-core@Pt-shell nanoparticles coated on platinum substrate exhibited good electro-catalytic properties and SERS activity for the oxidation of HCOOH, and the electro-oxidation proceeds of formic acid via "dual path" mechanism

牛顿亲自加工的轶事证实了牛顿与苹果的传奇故事吗

英国皇家学会是英国的科学院，牛顿曾任皇家学会主席。英国皇家学会今年迎来350周年纪念，将馆藏的部分珍贵手稿放到网上与公众分享是庆祝活动的一部分。 　英国皇家学会日前

沿流动方向折叠腔的优越性

本文通过模拟计算和对比分析了一个气动激光器的多种腔体内三维辐射场的分布、饱和增益分布、输出功率和效率,具体地显示出沿流动方向折叠腔的优越性.其基本规律也可供其他高速流动气动激光器作参考

横流放电CO↓2激光器能量转换的特性和机制

模拟计算分析了横流放电CO_2激光器中介质气压、流速、光腔位置、腔中辐射强度、输出耦合度等因素对介质各能态间能量转换特性的影响

激光器谐振腔中辐射能量密度须按场强叠加计算

原则上,激光腔中相干光的强度应由往返光束按场强叠加计算。本文比较按场强叠加和通常按光强叠加的计算,指出:腔中各处的饱和增益和光强确有可观的偏差,但场分布和输出功率很好地相符